A study analysing the whole-genome sequencing of more than 100,000 people in Iceland reveals some of the most detailed genetic portraits of a population yet.

Analysts used the latest DNA-reading technology to build a genetic portrait of Iceland, when previously scientists have used a system of switching off genes only in mice for studying what genes do and how they affect health. The study set out to answer the question: “What if we could find people in whom genes had been switched off due to rare mutations?”

Dr Kari Stefansson, a neurologist and CEO of the biopharmaceutical company that partly funded the study, said: “What we have is a fairly detailed insight into the sequence of the genome of an entire nation. This is a reasonably large step towards understanding how human diversity is dictated by diversity in the sequence of DNA.”

The Father of all Humans 239,000 Years Old

One of the major discoveries was a shifting in the estimation of how old the most recent common male ancestor is: previously a 2013 study from the University of Arizona estimates that the age of ‘the father of all humans’ would be 340,000 years old. But the results from this more recent study indicate he probably lived about 239,000 years ago, which is a much closer estimate to that of humanity’s most recent common female ancestor, who lived about 200,000 years ago. Of course 39,000 years can hardly be considered an insignificant age gap, but it does provide a closer time-frame between the two gender’s as previously believed.

Co-author of the study Agnar Helgason said: “[Humans] are curious about where we came from and how we became the way we are. This gives us a bit more information about when.” In terms of evolution, older species have more time to develop mutations that differ between individuals from one another. That means the age of the human species is also related to how diverse humans are as a whole.

Scientists also used the data from this study to identify 8,000 Icelanders have at least one gene that is completely mute, meaning that this particular gene does not function at all. Gene’s relating to the sense of smell were muted most commonly, but the researchers discovered 1,171 silenced genes, equating to nearly 8% of the 104,000 participants.

Genome Sequencing to Develop Treatments for Diseases

By looking further into the health of these individuals, directly examining the effects of genes on human biology researchers believe this could help in the development of drugs and diagnostics. Dr Stefansson said the results are “a demonstration of the unique power sequencing gives us for learning more about the history of our species and for contributing to new means of diagnosing, treating and preventing disease.”

He also suggests that because the study was conducted with a large proportion of such a small population that it can advance science on a worldwide scale. He said: “This is very much more than a molecular national selfie. We’re contributing to important tools for making more accurate diagnostics for rare diseases; finding new risk factor and potential drug targets for diseases like Alzeimer’s; and even showing how the Y chromosome, a loner in the paired world of our genome, repairs itself as it passes from father to son. Other countries are now preparing to undertake their own large-scale sequencing projects and I would tell them the rewards are great.”

DNA Sample Collection

Not everyone was in favour of the study, especially during its sample collection stages. Around 10 months ago, while DNA sample collections were still taking place, Alda Signumdsdottir spoke out. The Icelandic writer and journalist told the BBC: “I will not be emotionally blackmailed into giving my DNA – it’s my own private and personal information and I am not going to give it to anybody!”

Because of the nature of the study and the promise that a $20 dollar donation would be given to charity for every sample collected, she suggests that people may have felt guilty if they did not provide their DNA. She said: “It puts a lot of pressure on people. You sort of feel like you’re a bad person – you know, if I don’t give a sample [the charity] doesn’t get my donation. And I resent that kind of manipulation.”

When the subject was approached in a BBC interview of Dr Stefansson (also around 10 months ago) he countered: “No-one is forcing anyone to give their DNA and the National Biotheics committee suggested we use third parties to approach potential participants. But there is nothing wrong with trying to convince people to take part in biomedical research. Without making discoveries about the nature of disease, we are not going to advance medicine and we are in a privileged position in Iceland.”

Despite some passionate opposition to the approach the company took to encourage people to give samples they were able to complete their DNA testing analysis of over 100,000 participants, reporting it as a huge success.

DNA Testing Benefits

This study illustrates that a vast amount of discoveries can be made from the full sequencing of genetic code, for increased knowledge and developments for benefits applicable to people in general on a huge scale. On a smaller scale, but of much greater significance to you or those that you care about in particular, DNA testing can provide great benefits too. AlphaBiolab’s DNA testing could help you determine the true biological father of a child with a DNA paternity test, establish a relationship of a relative through complex DNA relationship testing or reunite family members using a DNA test for immigration purposes just to name a few.

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